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Michael Oliver
Katarina Ong
Connor Wilson
11 February 2014
Investigation 38 : What is the pH of Household Items
Experimental Background
The purpose of this Laboratory investigation was to determine the pH values of an
assortment of different household items, using three common tests for pH: Litmus
Paper, a pH meter, and a Universal Indicator
...

pH, in the most literal sense, is a measure of the concentration of hydrogen ions (H​+​) in
a given solution
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Many household cleaning agents, such as bleach and detergent, are basic, and
are good for breaking down dirt, oil, or stains
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Apparatus
Figure 1
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1

Figure 2
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Figure 3
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2

Figure 4
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The
blue litmus paper turns red when exposed to acidic solutions, and the red litmus paper
turns blue when exposed basic solutions
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00 pH and 10
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The household items were then tested for acidity and basicity using three methods
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The stirring rod was then rinsed with deionized water before repeating the
process with each of the other household liquids
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When blue litmus paper turned red, the item was acidic
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A pH meter
was calibrated using buffers that had a pH of 4
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00
...

The pH meter was then rinsed with deionized water, wiped off with a Kim Wipe, and
dipped into the next household liquid
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The last test was specifically saved for last because it would contaminate the entire
sample of the household item
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Two drops of universal indicator were added to each sample in the
spot plate, and the colors of the samples were then compared to the pre-made test
tubes in Figure 1
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​This table lists the twelve household items examined in this investigation, and
the results of the three tests performed on them, with quantitative and qualitative
observations included
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22

8
...
00

1
...
57

7
...
10

8
...
Clean

Red to Blue

medium blue

10
...
5

dark green

Lemon Juice

Blue to Red

strong red

2
...
5

orange

5

Vinegar

Blue to Red

medium red

2
...
0

light red

Mountain
Dew

Blue to Red

weak red

3
...
5

orange

Hand Lotion

No Change

little change

6
...
0

yellow

Suave
Shampoo

Blue to Red

weak red,
little change

5
...
5

orange

Barbasol
Shaving
Cream

No Change

little change

8
...
0

dark green

Kaboom Bowl
Blaster

Blue to Red

strong red

0
...
0

deep red

Data Processing
Table 2
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Acidic items were also indicated by blue litmus paper
turning red and by having a Universal Indicator pH value less than 7
...
00

Lemon Juice

2
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43

Mountain Dew

3
...
43

Table 3
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Basic items were indicated by red litmus paper turning
blue, and by the fact that their Universal Indicator pH value was significantly higher that
7
...
22

PineSol

9
...
10

Mr
...
03

Table 4
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Neutral items were determined to be items with a pH that was within
one or 2 pH units away from 7, and the litmus paper tested had little or no change in
color
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12

Suave Shampoo

5
...
21

Conclusion
The purpose of this laboratory investigation was to determine the pH value of a
collection of different household items
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These solutions included food items, such as lemon
juice and vinegar, as well as cleaning chemicals designed to remove mineral buildup on
household surfaces
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These solutions were all products intended for heavy cleaning, with
strong basic solutions being well suited to breaking up dirt and other grime
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These solutions were all
made from cosmetics products
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The Litmus paper test was the simplest of the tests, and was the first test performed on
the household product solutions
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Beyond this simple binary determination, there is little
information than can be gleaned from this test
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One additional issue with the litmus
test is that solutions of very high or very low pH have a tendency to bleach the litmus
paper, destroying any information that may have been gleaned
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The second pH test applied to the household solutions was the use of a pH meter to
obtain quantitative data about pH values
...
This
test, however, was also the most involved method employed in this investigation, and
required the calibration and careful maintenance of the pH meter so as to obtain the
most accurate readings, as well as to avoid contaminating the solutions to be tested
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The final test applied to the household chemicals in this investigation was the use of a
universal indicator, and a set of prepared solutions of known pH to compare to
...
One issue with the universal indicator test is that it requires the indicator
to be added to the solution being tested, potentially changing its pH and skewing the
results of the test
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